It may be necessary in exhaust systems of internal combustion engines for various reasons to guide or direct an exhaust gas stream within an exhaust gas path in a specific manner. For example, a dead water area in the area of a curve or bend of the exhaust gas path can thus be reduced. Furthermore, a more uniform flow distribution can be achieved in the expanded cross section by generating a swirl upstream of a cross section expansion. Furthermore, it may be necessary for various reasons to inject a liquid educt into the exhaust gas stream. For example, fuel may be injected into the exhaust gas stream upstream of an oxidation catalyst in order to induce an exothermic combustion reaction in an oxidation catalyst arranged downstream. Likewise, a reducing agent, for example, ammonia, may be injected, for example, into the exhaust gas stream in order to reduce nitrogen oxides entrained in the exhaust gas in an SCR catalytic converter arranged downstream. It is also possible to inject an aqueous ammonia solution into the exhaust gas stream instead of ammonia. Ammonia and water are then formed from the urea-water solution by a hydrolytic reaction. Furthermore, a fuel or another suitable reducing agent may be injected into the exhaust gas stream upstream of an NOX storage catalyst in order to regenerate the NOX storage catalyst.
To improve or make possible the mode of action of the educt injected in the liquid form into the exhaust gas line, extensive evaporation is just as desirable as an intensive mixing with the exhaust gas, in order to thus obtain the most homogeneous exhaust gas-educt mixture possible. The exhaust system may be equipped for this with a flow guide means, which is arranged in the exhaust gas line downstream of the injection means and is designed in a suitable manner as a mixing and/or evaporating means.